1. Technical Field
Embodiments of the present invention relate to an RF filter, more particularly to an RF filter with which it is possible to alter the bandwidth.
2. Description of the Related Art
Communication systems in recent times are evolving from 3G to 4G systems. Existing communication systems and advanced communication systems currently coexist. Under such circumstances, there have been researches focused on ways to utilize existing base station equipment, and one outcome of such researches is the technology of tunable filters.
With the advances in communication technology, the bandwidths of systems that employ existing communication systems are gradually decreasing, while the bandwidths of systems that employ newer communication systems are gradually increasing.
If an RF filter capable of altering its bandwidth and center frequency were developed, then it would be possible to remotely change the filter's bandwidth and center frequency according to advances in communication technology without replacing existing equipment.
Thus, there is a demand for a filter having a tunable, but existing studies have mainly focused on frequency-tunable filters and there have been relatively less research on filters capable of altering its bandwidth.